Distribution and evolution of sedimentary system in different types of basin edge：A case study of peripheral regions of Bodong Buried Hill, Dongying Sag

Based on core,logging,borehole and oil testing data,it was discussed in this paper the distribution of depositional systems and oil reservoir types in the upper subsection of the 4th member of the Shahejie Formation in the peripheral regions of the Bodong Buried Hill,the Dongying Sag.Due to strong source supply,delta sediments were widespread during the LST period in the eastern stable basin edge(the Guangrao Uplift).In the western active basin edge(the Bodong Buried Hill),sandy beach bar sediments generated as the result of source shortcoming.Meanwhile,the sedimentary boundary of beach bar moved southwards with the lifting of the Shicun Fault.During the TST and HST periods,carbonate beach bar sediments were common,and the scale of carbonate beach bar in active basin edge decreased;however,it had good physical properties because of weathering and leaching effects.The active basin edge has complex accumulation characteristics.Early stratigraphic reservoirs,late structural-lithologic reservoirs and carbonate lithologic reservoirs are the main exploration target.In the stable basin edge,only one trap type is found,indicating early stratigraphic reservoirs.